[PATCH v1 1/2] mm: add stubs for PFNMAP memory failure registration functions

[<ankita@nvidia.com>]

From: Ankit Agrawal <ankita@nvidia.com>

Add stubs to address CONFIG_MEMORY_FAILURE disabled.

Suggested-by: Alex Williamson <alex@shazbot.org>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
---
 include/linux/memory-failure.h | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/include/linux/memory-failure.h b/include/linux/memory-failure.h
index 7b5e11cf905f..d333dcdbeae7 100644
--- a/include/linux/memory-failure.h
+++ b/include/linux/memory-failure.h
@@ -4,8 +4,6 @@
 
 #include <linux/interval_tree.h>
 
-struct pfn_address_space;
-
 struct pfn_address_space {
 	struct interval_tree_node node;
 	struct address_space *mapping;
@@ -13,7 +11,18 @@ struct pfn_address_space {
 				unsigned long pfn, pgoff_t *pgoff);
 };
 
+#ifdef CONFIG_MEMORY_FAILURE
 int register_pfn_address_space(struct pfn_address_space *pfn_space);
 void unregister_pfn_address_space(struct pfn_address_space *pfn_space);
+#else
+static inline int register_pfn_address_space(struct pfn_address_space *pfn_space)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void unregister_pfn_address_space(struct pfn_address_space *pfn_space)
+{
+}
+#endif /* CONFIG_MEMORY_FAILURE */
 
 #endif /* _LINUX_MEMORY_FAILURE_H */
-- 
2.34.1